I think you'd have to be truly desperate or out of your mind to want to spend a night at Newark Penn Station. I have once spent quite a bit of a night there having arrived by a late Cardinal and missed the last NJT westbound to Metropark. Finally got on the 67. Phew! Not a very pleasant experience.
I had a nearly identical experience once at NY Penn station. It was a Friday night and I had a long layover connecting the Maple Leaf to "The Crazy Train" 67, which seems to board some nutty folks in the middle of the night. The blaring volume of the onboard announcements and the fact that the coach aisle lights are rarely dimmed (They had fortunately been turned off in BC where I was sitting) do little to ease the moods of the agitated passengers. I couldn't check my bags since the baggage department closed up shop for the night at the very moment of my arrival, and I didn't feel like paying to leave my luggage across the street at a hotel at midnight only to return at 3am to get set for the train's arrival.
So I sat in Penn Station where NJT would drop off loads of drunken party revelers who would often make awkward attempts to start conversations with me before their friends would signal them in the direction of their next drunken adventure. The only public bathroom in Penn Station was the biggest disgrace I have ever seen in the context of bathroom cleanliness. Every single imaginable form of excrement was present in the never-flushed-once-since-Guliani urinals, the floor looked like more of a landfill, and the smell was something you might expect from a community ravaged by the Bubonic Plague. The sporadic flow of drunk folks getting off their NJT trains made the atmosphere go from dead as a doorknob to burgeoning with laughter and shenanigans instantly. Some of the NJT-riding-drunkards would approach me to ask for their pictures to be taken, and were very kind and considerate towards me. Others were the sort of obnoxious hooligans who make you understand why American tourists are despised in many major European cities. Some of the folks in the ticketed passenger waiting area engaged in a ferocious shouting match over which direction the plug-in fans should face. Now that my ramble about my worst Penn Station overnight experience is done, if you have the chance to do so just find a place to sleep on Airbnb (they can be priced dirt-cheap if you're traveling solo) and use Uber to get around in the mean time.